If the mass of a crate is 50 kg and sliding friction is 100 n, what is acceleration when pulling force is 100 n?

-- The AMOUNT of the error was (10.24 m/s² minus 9.81² m/s ) = 0.43 m/s²

-- The error as a fraction of the true number was (0.43)/(9.81) =  0.0438 .  That's the decimal form of the error.

-- To change a number to a percentage, move the decimal point 2 places that way ==> .

0.0438  ==>  4.38% .

The error is positive, because the measurement was too big.